Spray and blow gun



United States Patent O SPRAY AND BLOW GUN Morley V. Friedell, Wheatridge, Colo., assignor to C. A. Norgren Co., a corporation of Colorado Application July 22, 1955, Serial No. 523,776

6 Claims. (Cl. 299-140) This invention relates to a combination blow and spray gun adapted to deliver a jet of air under pressure for cleaning a surface and also to spray a finely atomized mist of liquid material to be applied as a coating to the surface. It is a general object of the invention to provide a new and improved gun of the type described.

Another object of the invention is to provide a new and improved gun of the type described, adapted to be held and operated in one hand, and having a trigger which, on partial compression, causes a jet of air to issue from the nozzle of the gun and, on further compression, causes a finely atomized spray of liquid to. issue from the nozzle.

A further object is to provide a gun of the type described having a valve controlling the compressed air delivered to the gun which is held in closed position by an impressive force, thus minimizing the possibility of its being accidentally tripped in handling, but which, when opened, is partially counterbalanced, thus reducing the force necessary to hold the air valve open during operation.

Another object is to provide a spray gun having a liquid supply valve which may be manually opened in increments to control the density of liquid contained in the spray; which when fully opened provides a spray having a predetermined constant density of liquid, Yand which may be readily adjusted to determine the density of liquid in the spray when the valve is fully opened.

It is also an object to provide a spray gun having an improved arrangement of straight-line liquid passages to minimize clogging and permit the use of a variety of liquids, the liquid passages being of relatively small crosssection to avoid the entrapment of air or gases which would cause the gun to throw large drops of liquid, yet being capable of carrying heavy ows with uniform spray characteristics.

Another object of the invention is to provide a new and improved gun of the type described, of extremely simple construction, having a minimum number of parts forming a minimum number of air and liquid passages and with the air and liquid valves both located in a single bore to facilitate assembly and disassembly for cleaning and servicing.

A further object is to provide a new and improved spray gun which will operate over a wide range of pressure, with the liquid being supplied under pressure to the gun or being drawn by suction to the gun.

Other objects and advantages will become readily apparent from the following detailed description taken in connection with the accompanying drawings, in which:

Fig. l is an elevational view of a combination blow and spray gun embodying my invention;

Fig. 2 is an elevational view of the discharge end of the gun shown in Fig. l;

Fig. 3 is an enlarged, fragmentary sectional view taken on the line 3--3 of Fig. 2; and,

Fig. 4 is a fragmentary side elevational view showing a modification of the gun shown in Figs. l, 2 and 3.

ice

While illustrative embodiments of the invention are shown in the drawings and will be described in detail herein, the invention is susceptible of embodiment in many different forms, and I wish it'understood that the present disclosure is to be considered as an exemplilication of the principles of the invention and is not intended to limit the invention to the embodiments illustrated. The scope of the invention will be pointed out in the appended claims.

In the form illustrated in Figs. l, 2 and 3 of the drawings, the invention is embodied in a combination blow and spray gun 10 having a barrel portion 11 and a handle portion 12 which extends downwardly and rearwardly from the barrel portion, that is, downwardly and to the left, as the gun is viewed in Fig. l. The handle portion is provided with an air supply passage 13 and a liquid supply passage 14, each of which is threaded at the lower end to permit the connection of tubing leading respectively to a suitable source of air under pressure and a suitable supply of liquid. The air and liquid supply passages respectively communicate with an air delivery passage 15 and a liquid delivery passage 16, which direct the air and liquid to a discharge nozzle 17. The delivery passages are controlled respectively by an air valve 18 and a liquid valve 19 located in the barrel portion of the spray gun. The air and liquid valves are arranged to be opened by means of a manually compressible trigger 24) mounted exteriorly on the spray gun. Operation of the valves on compression of the trigger places the air andvliquid supply passages in communication with the discharge nozzle provided at the forward end of the barrel portion where the liquid is atomized and discharged as a spray. The spray gun may be fashioned with a hook 21 which facilitates hanging the gun ,on a convenient peg.

The gun is especially adapted for use in handling a liquid to be applied to surfaces in the form of a spray for lubricating purposes. On partial compression of the trigger, the air valve is first opened to cause ya jet of air under pressure to issue from the discharge nozzle to clean the surface to Which the lubricant is to be applied. On further compression of thetrigger, the liquid valve is opened, causing a supply of liquid to enter the air stream and emergev from the discharge nozzle in the form of a nely atomized spray suitable for lubricating the surface.

As shown, the barrel portion i1 is provided with a longitudinally extending bore 22 in which the air and liquid valves are operable and which encloses the air and liquid delivery passages which connect with the discharge nozzle 17. Formed in a stepped portion of the bore is an air chamber 23 having therein an annular valve seat 24 dividing the chamber into a first section 25y opening to the air supply passage 13, and a second section 26 which communicates with the air passage 15 by means of a plurality of openings 27 in a tubular operating stem 28 for the liquid valve 19. Air valve 18 includes an annular valve member 30 which is operable to engage the valve seat 24 and for this purpose is mounted on one end of a hollow valve stem 31, in turn threadably connected to a valve stem extension 32 which projects outwardly of the bore and carries the discharge nozzle 17. A spring 33 of relatively high compression strength is located in the bore and positioned to urge the valve member 30 against the valve seat 24, thereby to close off communication between the chamber sections 25 and 26.

The valve member 30 is opened by means of the trigger 20, which for this purpose is pivoted by a pin 34 to an ear 35 extending from the barrel portion 11 of the spray gun, the trigger being provided with a bifurcated portion 36 at its upper end which engages a locknut 37 threadedly mounted on the portion of the air valve stem extension 32 positioned exteriorly of the bore 22.` When the trigger 2i] is compressed by an operator, it pivots clockwise about the pin .34,thereby sliding the air valve stem to the right (Figs. 1 and 3) and opening the air valve 18 by separating the valve member 30 from its seat 24. As previously noted, the spring 33 which biases i' the air valve 18 to closed position is relatively strong, and thus a substantial amount of initial force is required to open the air valve. By this arrangement accidental triggering of the cun is prevented. Once the air valve is opened, however, air pressure may build up within the chamber section Z6, and this air pressure applied against the entire face of valve member 30 opposes the bias of the spring, and thus a good deal less force is required to maintain the valve in open position than is required to open the valve initially.

The liquid passage 16 is provided by a tube 4()V extending through the air passage and opening at its outer end in the discharge nozzle 17. The tube 40 is carried i by the tubular liquid valve operating stem 28 which is slidably mounted in the bore and forms the left-hand end of liquid passage 16. A valve seat 41 is formed by the end of passage 16. Liquid from supply passage 14 iiows into the passage 16 under thecontrol of a conically shaped valve member 42 which is adjustably mounted in the left-hand end of the bore by means of screw threads 43 for the purpose of controlling the volume of liquid delivery. A spring 44surrounds the tube 4i) `and bears against the end of the liquid valve operating stem 28 so as normally to close the valve. While the tube 40 is carried by stem 28 and is movable therewith, an additional guide means 45 is provided adjacent the discharge end of the tube to maintain the tube centered in the air is opened. To this end, a lost motion connection is provided between the air valve and the liquid valve to insure that the liquid valve can be opened only after the air valve has been opened. For this purpose, the stem 31 of the air valve is provided with a shoulder 50 which is engageable with a collar 51 provided on the operating stem 28 of the liquid valve, with the shoulder and collar being spaced from each other when both valves are in closed position. Only after the valve stem 31 has been moved sufliciently to open the air valve will the shoulder thereon engage the collar 51, whereby continued opening movement of the stem 31 will open the liquid valve.

The extent of movement of the stem 31 is determined by engagement of a collar 52, provided on the stem extension 32, with a step 53 formed in the bore.

In operating the embodiment of the invention thus far ing movement of the valve stem 31 to the right in Fig. 3,

thereby opening the air valve 18. With the air valve open, air ow may occur through the sections 25 and 26 of the chamber 23, and thence through openings 27 into the air passage 15 and hence through the nozzle 17.

Continued compression of the trigger 20 will move the air valve stem 31 to a position bringing its shoulder- 5t? into engagement with the collar 51 on the liquid valve stem, and further movement will open the liquid valve. At this point, slight movement of the trigger 20 results in a corresponding slight relative movement between the valve seat 41 and valve 42, thereby regulating the volume of liquid which may enter the liquid passage 16. When the trigger is completely compressed, the collar 52 is in engagement with the step 53, and yat this point a predetermined maximum amount of liquid is permitted to pass the liquid valve 19 and into the liquid `delivery passage 16. Adjustment of the maximum ilow may readily be had by rotating the valve 42, thereby changing the spacing between the valve and the wide open position of the valve seat 41.

, The flow of air in passage 15 past thewend of the tube 44) located in the discharge nozzle reduces the pressure at that point sufficiently to draw liquid upwardly a substantial -distance and into the supply passage 14. Thus the source of liquid need not be under pressure in order for the gun of the present invention to operate eiciently. It will also be noted that the liquid delivery passage 16 has a relatively small diameter, and provides a straight-through ilow from the portion of the bore wherein the liquid valve 19 is located to the discharge nozzle,

i and that that portion of the bore is supplied directly with liquid from the liquid supply passage 14. Because of this arrangement, there is no entrapment of air or gases in the liquid, nor are any air or gas pockets provided which would cause the gun to emit large slugs or drops of liquid. In addition, the liquid passage is completely surrounded by the air passage, which conducts air under pressure, and for this reason leakage of liquid into portions of the gun other than the liquid passages provided therefor is prevented, or at least greatly reduced. Thus the spray and blowgun of the present invention does not require cleaning at frequent intervals.

The gun may be quickly disassembled simply by removing the pin 34 about which the trigger pivots and unscrewing the retainer nut 54, whereupon the entire air and liquid control mechanism may be removed as a unit from the main bore 22. If complete disassembly is desired, this may be accomplished by then unscrewing the nozzle 17 and the locknut 37 and unscrewing the parts 31 and 32 forming the air valve stern. Normally, however, complete disassembly will not be required as no liquid will ever enter the air valving, the air chambers or air passages. When normal ushing of the gun with the valve assembly removed is insuicient for cleaning, cleaning may be further facilitated by removing the valve 42, thus providing a straight-through passage from the front to the rear of the barrel portion 11.

In Fig. 4, there is illustrated a modication of the gun described above, including an extension tube which may be attached to the gun. The extension tube is utilized by merely removing the discharge nozzle 17 and replacing it with a tubing adaptor 60 which is screwed into the forward end of the air valve stern extension 32. A suitable length of tubing 61, which may be as long as four feet, is then installed in the adaptor 60, andthe outer end of the tubing 61 is provided with a discharge nozzle 62. The tubing may be bent or formed to direct the spray as dcsired, as in deep drawing dies, or merely for safety to avoid reaching into hazardous locations.

The use of the gun with the extension tube 61 represents an added advantage while retaining advantages attendant the form of the Figs. l, 2 and 3. When the gun is used with the extension tube, the liquid should be supplied underpressure to the supply passage 14.

I claim: y

1. A spray and blow gun having a handle portion and a barrel portion, a bore extending longitudinally through the barrel portion, a discharge nozzle at one end of the barrel portion, an air delivery passage extending through the bore and opening at one end in the discharge nozzle, a tubular member slidably mountedtin the bore and extending through the air delivery passage, said tubular member providing a liquid `delivery passage opening at one end in the discharge nozzle and a valve seat at the other end of the liquid delivery passage, a liquid supply passage opening into Ithe bore adjacent said seat, a liquid valve member mounted in the end of the bore adjacent `said seat, means biasing the tubular member toward said manually operable trigger on theV gun connected to open the air valve upon initial movement thereof and then to slide the tubular member to unseat the liquid valve mem' ber upon further movement thereof.

2. A spray and blow gun having a handle portion and a barrel portion, a bore extending longitudinally through the barrel portion, a discharge nozzle at one end of the barrel portion, an air delivery passage extending through v the bore and opening at one end in the discharge nozzle, a tubular member slidably mounted in the bore and extending through the air delivery passage, said tubular member providing a substantially straight line liquid delivery passage of small diameter opening at one end in the discharge nozzle, a valve seat at the other end of the liquid delivery passage, a liquid supply passage opening into the bore adjacent said seat, a liquid valve member mounted in the end of the bore adjacent said seat, means positioned exteriorly of the bore for moving said liquid valve member toward and away from said seat to 'adjust the volume of liquid flow from the liquid supply passage into the liquid delivery passage when said liquid valve member is unseated from the seat, means biasing the tubular member toward said other end of the bore to engage the seat with the liquid valve member, an air valve controlling the air delivery passage, and a manually operable trigger on the gun connected to open the air valve upon initial movement thereof and then to slide the tubular member to unseat the liquid valve member upon further movement thereof.

3. A spray and blow gun having a handle portion and a barrel portion, a bore extending longitudinallythrough the barrel portion, a discharge nozzle at one end of the barrel portion, an air delivery passage extending through the bore and opening at one end in the discharge nozzle, a liquid delivery passage extending through the bore and opening at one end in the discharge nozzle, a chamber in the bore at the other end of the air delivery passage, an air supply passage communicating with the chamber and adapted to be connected to a source of air under pressure, a valve seat in the chamber dividing the same into a first section opening to the air supply passage and a second section communicating with the air delivery passage, an air valve movable toward and away from said seat to control communication between said sections of the chamber, means biasing the air Valve toward said seat, a liquid supply passage communicating with the liquid delivery passage, a liquid valve controlling the liquid delivery passage, and a manually operable trigger on the gun connected to open sequentially the air valve and then the liquid valve, with, the air pressure in said second section of the chamber operating on the air valve to offset at least in part the bias of said biasing means.

4. A spray and blow gun having a handle portion and a barrel portion, a bore extending longitudinally through the barrel portion, a discharge nozzle at one end of the barrel portion, a tubular valve stem extending longitudinally of the bore and slidably mounted therein with the hollow of the stem providing an air delivery passage opening at one end in the discharge nozzle, a chamber in the bore at the other end of the valve stern, an air supply passage opening into the chamber and adapted to be connected to a source of air under pressure, an annular valve seat in the chamber and dividing the same into a` first section into which said air supply passage opens and a second section communicating with the air delivery passage, an annular air valve on said other end of the valve stem and movable therewith toward and away from said seat to control communication between said sections member slidably mounted in the bore and carrying said tubular member, said seat-forming member being provided with a passageway interconnecting the Valve seat opening with the liquid passage, a liquidvalve member mounted in the end of the bore adjacent the seat formed by said seat-forming member, means biasing the seatforming member toward said other end of the bore to engage the seat thereon with the liquid valve member, a

liquid supply passage opening into the bore adjacent the liquid valve member, a manually operable trigger on the gun and connected to said valve stern to move the same to unseat the annular air valve, and a lost motion connection between the valve stem and the seat-forming member to unseat the liquid valve member only after the air valve is open.

5. A spray and blow gun having a handle portion and a barrel portion, a bore extending longitudinally through the barrel portion, a discharge nozzle at one end of the barrel portion, a tubular valve stem extending longitudinally of the bore and slidably mounted therein with the hollow of the stem providing an air delivery passage opening at one end in the discharge nozzle, a chamber in the bore at the other end of the valve stern, an air supply passage opening into the chamber and adapted to be connected to a source of air under pressure, an annular valve seat in the chamber and dividing the same into a rst section into which said air supply passage opens and a second section communicating with the air delivery passage, an annular air valve on said other end of the valve v stem and movable therewith toward and away from said seat to control communication between said sections of the chamber, means biasing the valve stem toward movement in a direction to engage the valve with the seat, a tubular member extending through said hollow of the valve stem and providing a liquid passage opening at one end in the discharge nozzle, a valve seat-forming member slidably mounted in the bore and carrying said tubular member, said seat-forming member being provided with a passageway interconnecting the valve seat opening with the liquid passage, a liquid valve member mounted in the end of the bore adjacent the seat formed by said seatforming member, means biasing the seat-forming member toward said other end of the bore to engage the seat thereon with the liquid valve member, a liquid supply passage opening into the bore adjacent the liquid valve member, a manually operable trigger on the gunand connected to said valve stem to move the same to unseat the annular air valve, and a retaining nut threadedly mounted on said barrel and retaining said valve stem, tubular member and seat-forming member in position therein, said retaining nut being readily removable to permit the valve stem, tubular member and seat-forming member to be removed from the bore.

6. A spray and blow gun having a handle portion and a barrel portion, a bore extending longitudinally through the barrel portion, means slidably mounted in the bore and forming an air passage and a liquid passage extending therethrough, a discharge nozzle at the end of the bore in which said passages terminate, means including said passage-forming means providing an air valve controlling the air passage and a liquid valve controlling the liquid passage, and a retaining member threadedly mounted on the barrel and retaining all of said means in position within the bore with said means being sldable out of the bore upon removal of said retaining member.

References Cited in the le of this patent UNITED STATES PATENTS 1,651,466 Norris Dec. 6, 1927 2,469,642 Crewe May 14, 1949 2,633,150 Lewis Mar. 31, 1953 

